Clinical effectiveness and safety of gemifloxacin versus cefpodoxime in acute exacerbation of chronic bronchitis: A randomized, controlled trial

Assessing Treatment Success or Failure as an Outcome in Randomised Clinical Trials of COPD Exacerbations. A Meta-Epidemiological Study

A recently published ERS core outcome set recommends that all trials of COPD exacerbation management should assess the treatment success (or “cure” of the exacerbation), defined as a dichotomous measure of the overall outcome of an exacerbation. This methodological systematic review describes and compares the instruments that were used to assess treatment success or failure in 54 such RCTs, published between 2006–2020. Twenty-three RCTs used composite measures consisting of several undesirable outcomes of an exacerbation, together defining an overall unfavourable outcome, to define treatment failure. Thirty-four RCTs used descriptive instruments that used qualitative or semi-quantitative descriptions to define cure, marked improvement, improvement of the exacerbation, or treatment failure. Treatment success and failure rates among patients receiving guidelines-directed treatments at different settings and timepoints are described and could be used to inform power calculations in future trials. Descriptive instruments appeared more sensitive to treatment effects compared to composite instruments. Further methodological studies are needed to optimise the evaluation of treatment success/failure. In the meantime, based on the findings of this systematic review, the ERS core outcome set recommends that cure should be defined as sufficient improvement of the signs and symptoms of the exacerbation such that no additional systemic treatments are required.

Antibiotics for exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Many patients with an exacerbation of chronic obstructive pulmonary disease (COPD) are treated with antibiotics. However, the value of antibiotics remains uncertain, as systematic reviews and clinical trials have shown conflicting results.

OBJECTIVES

To assess effects of antibiotics on treatment failure as observed between seven days and one month after treatment initiation (primary outcome) for management of acute COPD exacerbations, as well as their effects on other patient-important outcomes (mortality, adverse events, length of hospital stay, time to next exacerbation).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, MEDLINE, Embase, and other electronically available databases up to 26 September 2018.

SELECTION CRITERIA

We sought to find randomised controlled trials (RCTs) including people with acute COPD exacerbations comparing antibiotic therapy and placebo and providing follow-up of at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references and extracted data from trial reports. We kept the three groups of outpatients, inpatients, and patients admitted to the intensive care unit (ICU) separate for benefit outcomes and mortality because we considered them to be clinically too different to be summarised as a single group. We considered outpatients to have a mild to moderate exacerbation, inpatients to have a severe exacerbation, and ICU patients to have a very severe exacerbation. When authors of primary studies did not report outcomes or study details, we contacted them to request missing data. We calculated pooled risk ratios (RRs) for treatment failure, Peto odds ratios (ORs) for rare events (mortality and adverse events), and mean differences (MDs) for continuous outcomes using random-effects models. We used GRADE to assess the quality of the evidence. The primary outcome was treatment failure as observed between seven days and one month after treatment initiation.

MAIN RESULTS

We included 19 trials with 2663 participants (11 with outpatients, seven with inpatients, and one with ICU patients).For outpatients (with mild to moderate exacerbations), evidence of low quality suggests that currently available antibiotics statistically significantly reduced the risk for treatment failure between seven days and one month after treatment initiation (RR 0.72, 95% confidence interval (CI) 0.56 to 0.94; I² = 31%; in absolute terms, reduction in treatment failures from 295 to 212 per 1000 treated participants, 95% CI 165 to 277). Studies providing older antibiotics not in use anymore yielded an RR of 0.69 (95% CI 0.53 to 0.90; I² = 31%). Evidence of low quality from one trial in outpatients suggested no effects of antibiotics on mortality (Peto OR 1.27, 95% CI 0.49 to 3.30). One trial reported no effects of antibiotics on re-exacerbations between two and six weeks after treatment initiation. Only one trial (N = 35) reported health-related quality of life but did not show a statistically significant difference between treatment and control groups.Evidence of moderate quality does not show that currently used antibiotics statistically significantly reduced the risk of treatment failure among inpatients with severe exacerbations (i.e. for inpatients excluding ICU patients) (RR 0.65, 95% CI 0.38 to 1.12; I² = 50%), but trial results remain uncertain. In turn, the effect was statistically significant when trials included older antibiotics no longer in clinical use (RR 0.76, 95% CI 0.58 to 1.00; I² = 39%). Evidence of moderate quality from two trials including inpatients shows no beneficial effects of antibiotics on mortality (Peto OR 2.48, 95% CI 0.94 to 6.55). Length of hospital stay (in days) was similar in antibiotic and placebo groups.The only trial with 93 patients admitted to the ICU showed a large and statistically significant effect on treatment failure (RR 0.19, 95% CI 0.08 to 0.45; moderate-quality evidence; in absolute terms, reduction in treatment failures from 565 to 107 per 1000 treated participants, 95% CI 45 to 254). Results of this trial show a statistically significant effect on mortality (Peto OR 0.21, 95% CI 0.06 to 0.72; moderate-quality evidence) and on length of hospital stay (MD -9.60 days, 95% CI -12.84 to -6.36; low-quality evidence).Evidence of moderate quality gathered from trials conducted in all settings shows no statistically significant effect on overall incidence of adverse events (Peto OR 1.20, 95% CI 0.89 to 1.63; moderate-quality evidence) nor on diarrhoea (Peto OR 1.68, 95% CI 0.92 to 3.07; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Researchers have found that antibiotics have some effect on inpatients and outpatients, but these effects are small, and they are inconsistent for some outcomes (treatment failure) and absent for other outcomes (mortality, length of hospital stay). Analyses show a strong beneficial effect of antibiotics among ICU patients. Few data are available on the effects of antibiotics on health-related quality of life or on other patient-reported symptoms, and data show no statistically significant increase in the risk of adverse events with antibiotics compared to placebo. These inconsistent effects call for research into clinical signs and biomarkers that can help identify patients who would benefit from antibiotics, while sparing antibiotics for patients who are unlikely to experience benefit and for whom downsides of antibiotics (side effects, costs, and multi-resistance) should be avoided.

Antibiotics for exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Many patients with an exacerbation of chronic obstructive pulmonary disease (COPD) are treated with antibiotics. However, the value of antibiotics remains uncertain as systematic reviews and clinical trials have shown conflicting results.

OBJECTIVES

To assess the effects of antibiotics in the management of acute COPD exacerbations on treatment failure as observed between seven days and one month after treatment initiation (primary outcome) and on other patient-important outcomes (mortality, adverse events, length of hospital stay).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and other electronically available databases up to September 2012.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in people with acute COPD exacerbations comparing antibiotic therapy and placebo with a follow-up of at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references and extracted data from trial reports. We kept the three groups of outpatients, inpatients and patients admitted to the intensive care unit (ICU) separate for benefit outcomes and mortality because we considered them to be clinically too different to be summarised in one group. We considered outpatients to have a mild to moderate exacerbation, inpatients to have a severe exacerbation and ICU patients to have a very severe exacerbation. Where outcomes or study details were not reported we requested missing data from the authors of the primary studies. We calculated pooled risk ratios (RR) for treatment failure, Peto odds ratios (OR) for rare events (mortality and adverse events) and weighted mean differences (MD) for continuous outcomes using fixed-effect models. We used GRADE to assess the quality of the evidence.

MAIN RESULTS

Sixteen trials with 2068 participants were included. In outpatients (mild to moderate exacerbations), there was evidence of low quality that antibiotics did statistically significantly reduce the risk for treatment failure between seven days and one month after treatment initiation (RR 0.75; 95% CI 0.60 to 0.94; I(2) = 35%) but they did not significantly reduce the risk when the meta-analysis was restricted to currently available drugs (RR 0.80; 95% CI 0.63 to 1.01; I(2) = 33%). Evidence of high quality showed that antibiotics statistically significantly reduced the risk of treatment failure in inpatients with severe exacerbations (ICU not included) (RR 0.77; 95% CI 0.65 to 0.91; I(2) = 47%) regardless of whether restricted to current drugs. The only trial with 93 patients admitted to the ICU showed a large and statistically significant effect on treatment failure (RR 0.19; 95% CI 0.08 to 0.45; high-quality evidence).Evidence of low-quality from four trials in inpatients showed no effect of antibiotics on mortality (Peto OR 1.02; 95% CI 0.37 to 2.79). High-quality evidence from one trial showed a statistically significant effect on mortality in ICU patients (Peto OR 0.21; 95% CI 0.06 to 0.72). Length of hospital stay (in days) was similar in the antibiotics and placebo groups except for the ICU study where antibiotics statistically significantly reduced length of hospital stay (mean difference -9.60 days; 95% CI -12.84 to -6.36 days). One trial showed no effect of antibiotics on re-exacerbations between two and six weeks after treatment initiation. Only one trial (N = 35) reported health-related quality of life but did not show a statistically significant difference between the treatment and control group.Evidence of moderate quality showed that the overall incidence of adverse events was higher in the antibiotics groups (Peto OR 1.53; 95% CI 1.03 to 2.27). Patients treated with antibiotics experienced statistically significantly more diarrhoea based on three trials (Peto OR 2.62; 95% CI 1.11 to 6.17; high-quality evidence).

AUTHORS' CONCLUSIONS

Antibiotics for COPD exacerbations showed large and consistent beneficial effects across outcomes of patients admitted to an ICU. However, for outpatients and inpatients the results were inconsistent. The risk for treatment failure was significantly reduced in both inpatients and outpatients when all trials (1957 to 2012) were included but not when the analysis for outpatients was restricted to currently used antibiotics. Also, antibiotics had no statistically significant effect on mortality and length of hospital stay in inpatients and almost no data on patient-reported outcomes exist. These inconsistent effects call for research into clinical signs and biomarkers that help identify patients who benefit from antibiotics and patients who experience no effect, and in whom downsides of antibiotics (side effects, costs and multi-resistance) could be avoided.